Accession Number:

ADA454209

Title:

The Noble-Abel Equation of State: Thermodynamic Derivations for Ballistics Modelling

Descriptive Note:

Technical note

Corporate Author:

DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION EDINBURGH (AUSTRALIA) WEAPONS SYSTEMS DIV

Personal Author(s):

• Johnston, Ian A.

Report Date:

2005-11-01

Pagination or Media Count:

27.0

Abstract:

Accurate modeling of gun interior ballistics promotes more efficient gun and propelling charge design. In order to simulate interior ballistic flowfields, such models require a description of the thermodynamic behaviour of the propellant gas. The Noble-Abel equation provides a simple and reasonably accurate equation of state for propellant gases at the high densities and temperatures experienced in guns. Most computational fluid dynamics-based ballistics models, however, require additional thermodynamic functions which must be derived from the equation of state. This note presents the derivation of such thermodynamic functions for Noble-Abel gases. Although the derivations are geared toward the functional requirements of the commercial Fluent code, the results are equally applicable to all computational fluid dynamics solvers. Also presented is a brief numerical example for a typical propellant highlighting the different thermodynamics of the Noble-Abel and ideal gas equations.

Descriptors:

• *GUNS
• *THERMODYNAMIC PROPERTIES
• *PROPELLING CHARGES
• *INTERIOR BALLISTICS
• *EQUATIONS OF STATE
• EFFICIENCY
• COMPUTATIONAL FLUID DYNAMICS
• GASES
• AUSTRALIA
• PROPELLANTS
• FLOW FIELDS

Subject Categories:

• Guns
• Ballistics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE